Wavefront sensing method for diffraction optical system based on phase diversity

In this paper, we present a novel wavefront sensing method for diffraction optical system based on phase diversity. Based on the physical-imaging mechanism of diffractive optical system, the wavefront characteristics of the diffraction optical system are characterized by using diffraction efficiency. On this basis, a novel modified phase diversity (PD) wavefront sensing method is established based on the blocking idea. After that, the global optimization method of corresponding method based on particle swarm optimization algorithm is proposed. Finally, some experiment results are achieved with the experiment on a membrane diffraction optical system. Experimental results indicate that the proposed algorithm performs well on both wavefront reconstruction and image restoration and is far superior to traditional methods in diffraction optical systems. The accuracy of our proposed PD method is at least two orders of magnitude higher than the traditional method. Taking the 0.01 degrees field of view for example, our modified PD method can achieve the accuracy of 2.5 x 10(-4) wavelength when the diffraction efficiency is higher than 0.6. This proposed method can be applied to improve the image quality of the diffraction optical system and further support the on-orbit application of ultra-large aperture membrane imaging technology.